Seal



Feb. 1.1, 1.969 W, J, MARUUC 3,426,934

SEAL

Filed Dec. 20, 1966 wmf/faz;

United States Patent C) 3,426,934 SEAL Walter J. Marulic, Gary, Ind., assignor, by mesne assignments, to Union Tank Car Company, a corporation of Delaware Filed Dec. 20, 1966, Ser. No. 603,213

U.S. Cl. 220-26 Int. Cl. B65d 87/ 20 4 Claims ABSTRACT F THE DISCLOSURE This invention relates in general to floating roof storage tanks of the type generally used in storing volatile liquids such as petroleum products and the like. It deals more particularly with a seal arrangement and method of mounting a tubular, toroidal seal in a floating roof storage tank.

It is an object of the present invention to provide an improved seal arrangement of the tubular toroidal seal type.

It is another object to provide a seal arrangement which facilitates simple installation and removal of a flexible tubular seal from the rim of a floating roof with minimal effort.

It is still another object to provide a Seal arrangement whose vertical position on the floating roof rim can easily be varied in the field.

It is yet another object to provide a seal arrangement that is effective, inexpensive in materials, economical in shop and field labor, and can easily and rapidly be installed and removed while the tank is floating on a stored liquid.

It is a further object to provide a new and improved method of mounting a tubular seal on the roof of a floating roof storage tank.

The foregoing and other objects are realized in accord with the present invention by providing a seal arrangement comprising a fabric casing, sections of flexible foam plastic buns for enclosure by the fabric casing, and metal bands which strap the fabric to the floating roof rim by running entirely around the circumference of the roof above and below suitably disposed vertical rim bars. There is no need for punching bolt holes in the fabric seal or for laboriously and precisely punching bolt holes in the top of the floating roof rim. The horizontal strapping bands are all that is required to hold the seal on the roof rim. In mounting the sealing arrangement, the casing, consisting of a rectangular flat piece of elastomer-coated fabric with loops on its surface, is clamped along its upper edge to the upper edge of the annular roof rim. The casing depends over vertical rim bars shop welded to the rim. Strapping bands assembled with turn buckles to keep them in tension are passed through the aforementioned loops on the c-asing to hold the envelope tightly against the roof rim on the vertical rim bars with the casing filled with flexible foam plastic buns which provide the seal with resiliency. The preliminary clamps are removed from the casing.

The invention, both as to its organization and method of operation, taken with further objects and -advantages thereof, will best be understood -by reference to the accompanying drawings, in which:

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FIGURE 1 is a partial front elevational view of the toroidal seal casing as it would appear lying flat before assembling in the seal arrangement;

FIGURE 2 is a sectional View taken through the rim of the roof of a floating roof storage tank, with the envelope pictured in FIGURE 1 arranged in the initial step of mounting the seal arrangement according to the present arrangement;

FIGURE 3 is a view similar to FIGURE 2, also showing the tank wall and the foam plastic material used to fill the seal casing, all in an intermediate stage of mounting the seal arrangement on the roof rim;

FIGURE 4 is an enlarged sectional view of the seal arrangement as it is finally mounted between the floating roof rim and the tank wall; and

FIGURE 5 is an enlarged view of a strapping and turnbuckle assembly utilized in mounting the seal arrangement on the tank roof rim according to the present invention.

As previously pointed out, the present invention relates to a floating roof tank of the type used to store volatile petroleum products. Typically, in such a tank, a roof floats on the surface of a stored liquid within the tank, substantially eliminating any space between the liquid and the roof in which vapors might accumulate. The tank is normally cylindrical in shape and relatively large in diameter; an exemplary tank might be feet in diameter, for example.

The roof is circular, and is so constructed that it has a diameter slightly less than the diameter of the cylindrical wall of the tank, leaving an annular space between the peripheral rim of the tank and the wall thereof. The width of this space might vary from tank to tank, of course, and, in addition, vary in width around the same tank because of irregularities in construction, metal expansion and contraction and the like. The space width might vary between 6 and l2 inches or more.

To prevent the escape of vapors from the stored liquid through the aforementioned space between the tank roof and wall, a flexible sealing arrangement 10 embodying features of the present invention is mounted (see FIG- URE 4) on the annular rim 11 of the roof 12 between the roof and the tank wall 13. The sealing arrangement 10 includes an envelope 20, a series of vertical rim bars 21 welded in horizontally spaced relationship around the outer periphery of the annular rim 11 on the roof 12, a series of flexible foam plastic buns 22 retained within the envelope to provide necessary resilience, and a pair of strapping band and turnbuckle assemblies 23 and 24 which extend around the sealing arrangement according to the present invention and retain it tightly against the annular rim l1.

Referring now to FIGURE l, the envelope 20 consists of an elongated, rectangular, flat casing of elastomercoated fabric 30. The length of the rubberized fabric casing 30 is substantially identical to the circumference of the rim 11 on the tank roof 12. The width of the casing 30, on the other hand, is sufllcient to permit it to completely enclose a foam plastic bun 22, in the manner illustrated in FIGURE 4. The relationship of the mounted casing 30 and enclosed bun 22 permit the bun to roll upon its axis as the tank roof changes its direction of travel within the tank wall, thus `changing the compression axis of the plastic foam.

The elastomer coated fabric casing 30 is folded upwardly along its lower edge 31 to form a loop 32 extending along the bottom of the casing. The free edge 31 is secured to the inner face of the casing 30 by vulcanization or the like. Actually, the loop 32 comprises a series of loop segments 32a' separated by cut-outs taken from the loop every 20 feet along its length to provide a series of evenly spaced openings 33 in the loop. As will hereinafter be discussed in detail, it is through these openings 33 that the strapping and turnbuckle assemblies 23 is introduced and adjusted.

Intermediate the loop 32 and the upper edge 35 of the elastomer-coated fabric casing are secured a series of vertically disposed, horizontally spaced loops 40. The loops are on the opposite side of the easing 30 from the loop 32, as illustrated in FIGURE 2, and also secured thereto by vulcanization. A plurality of these loops are spaced along the length of the casing 30 on approximately five foot centers. The loops 40 are adapted to receive the other band and turnbuckle assembly 24 in a manner hereinafter discussed.

To assemble the seal arrangement 10 in the annular rim 11 of the roof 12, the elastomer-coated fabric casing 30 is first clamped along its upper edge 35 to the upper periphery of the rim 11, as illustrated in FIGURE 2, with conventional C-clamps 45. The clamps are spaced evenly around the rim 11 and the casing 30 is drawn taut underneath them. The overlapping free ends of the casing 30 are suitably spliced together.

With the casing 30 clamped in the manner illustrated in FIGURE 2, it depends around the annular rim 11 of the roof 12 over a spaced series of vertically extending rim bars 21. These rim bars 21 are formed of Plain steel bar stock and are preferably 3%. inch wide, 3%: inch thick, and 41/2 inches long. The bars 21 are welded to the periphery of the rim 11. These vertically extending rim bars 21 are spaced on approximately four foot centers around the periphery of the roof. They have rounded edges to avoid damaging the casing 30.

The casing 30 is now disposed as illustrated in FIG- URE 2, depending over the vertically disposed rim bars 21. At this point, the static drain straps 42 are fastened to the lower edge of the rim 11 after pulling the casing 30 up to permit this. The static drain straps 42 are also secured to the upper edge of the rim 11 (see FIGURE 4). The band and turnbuckle assembly 23 is then assembled through the loops 40. In this light, the band and turnbuckle assembly 23 comprises a series of stainless steel band strips and a series of interconnecting conventional turnbuckles 51.

The number of band strips 50 required to extend through the loops 40 around the entire casing 30 is determined by counting the number of twenty foot sections 32a of the loop 32. One twenty foot strip ,50 for each loop section 32a is then connected to one end of a turnbuckle 51 in a well known manner. These separate band strips 50 and turnbuckles 51 are then each inserted through appropriate loops 40 and the band strips are connected to the free ends of adjoining turnbuckles to complete the assembly 23. Suitable adjustment may be made in the length of one strap 50 to make the assembly 23 precisely extend the entire length of the casing 30.

With the band and turnbuckle assembly 23 extending through the loops 40 on the outside of the casing 30, the turnbuckles 51 are tightened around the entire roof 12. This process involves two men working 180 degrees apart on the roof 12 tightening turnbuckles 51. With the band and turnbuckle assembly 23 drawn tight in the loops 40, the casing 30 is pressed against the rim 11 of the floating roof 12 immediately below the vertically disposed rim bars 21, as illustrated in FIGURE 3.

At this point, the upper edge 35 of the envelope 30 is gripped and pulled upwardly to be sure the band and turnbuckle assembly 23 is seated tightly underneath the rim bars 21. Then a prescribed number of individual buns 22 of polyurethane foam are set down into the casing 30 from the top of the roof 12, as illustrated in FIG- URE 3. Each bun 22 is ten to twenty feet in length and octagonal in cross-section. They are each compressed approximately six inches in length to fit snugly in the envelope 20 formed by the casing 30.

At this point, the band and turnbuckle assembly 24 is threaded through the loop sections 32a of the loop 32 formed on the lower edge of the envelope (now pulled into the position seen in FIGURE 3). The assembly 24 is assembled through the loop 32 in the same way the assembly 23 was assembled through the loops 40.

At the same time, all of the C-clamps 45 clamping the upper edge 35 of the casing 30 to the upper periphery of the rim 11 are removed. The band and turnbuckle assembly 24 is then tightened by drawing the turnbuckles 51 tight to draw the loop 32 tight against the upper edge 35 of the envelope 20 and the rim 11, immediately above the vertical rim bars 21. The envelope 20 is thus completed and holds the foam buns 22 completely enclosed.

With the band and turnbuckle assembly 24 drawn tight, drawing the casing tight against the upper periphery of the rim 11 on the roof 12, it will be seen that the envelope 20 with its enclosed foam plastic buns 22 is anchored to the rim above and below the vertically extending rim bars 21. No holes had to be cut in the casing 30, nor were any bolt holes necessarily cut in the rim 11 of the roof 12. The seal arrangement 10 is retained against the rim 11 solely `by the band assemblies 23 and 24 extending through the loops 32 and 40, in cooperation with the rim t1 and the vertically disposed rim bars 21.

If it is desired to raise or lower the seal assembly 10 with respect to the rim 11 and, accordingly, the liquid surface, provision can be made for effecting the change by having duplicate or triplicate sets of rim bars 21 welded to the rim 11 at various elevations. The seal assembly 10 is then removed by releasing the band and turnbuckle .assemblies 23 and 24 and replaced at a different level.

I claim:

1. In a floating roof storage tank, a seal arrangement for providing an effective seal between the rim of the floating roof and the tank wall, comprising: an elongated casing of flexible material extending around the roof rim, said casing being folded upon itself to form a horizontally disposed envelope, resilient means in said envelope for pressing it into sealing relationship against the rim and the wall, vertically extending first loop means on said envelope disposed horizontally around said envelope, vertically extending second loop means on said envelope disposed horizontally around said envelope above said first loop means, locating means on said rim extending radially therefrom between said first and second loop means, tirst horizontally extending band means threaded through said first loop means around said rim to clamp said envelope against said rim, second horizontally extending band means threaded through said second loop means around said rim to clamp said envelope against said rim.

2. The seal arrangement of claim 1 further characterized in that said locating means comprises a horizontally spaced series of vertically disposed rim bars extending radially from said rim.

3. The seal arrangement of claim 1 further characterized in that said second loop means is formed along one longitudinal edge of said casing, and said first loop means is formed on one surface of said casing intermediate its longitudinal edges.

4. A method of constructing a seal arrangement on the rim of the floating roof` in a floating roof storage tank, comprising the steps of: providing a generally rectangular piece of casing material having a length substantially equal to the circumference of the roof rim, forming first loop means along one surface of the casing intermediate its longitudinal edges, forming second loop means along one of said longitudinal edges of said casing, attaching a mounting and positioning means on said rim so that it extends radially outwardly therefrom, temporarily clamping the other of said longitudinal edges of said casing to said roof rim so that said casing hangs downwardly around said rim and over said mounting and positioning means, passing band means through said first loop means below said mounting and positioning means and drawing said first band means tight around said rim to clamp said casing tightly against said rim below said mounting and positioning means, drawing said one longitudinal edge of said casing upwardly so as to form an envelope with said casing, positioning flexible, resilient means in said envelope around the circumference of said rim, passing second band means through said second loop means, and drawing said second band means tight to draw said envelope closed and clamp said one longitudinal edge of said casing tightly against the other longitudinal edge thereof and against said tank rim, and removing said temporary clamping.

References Cited UNITED STATES PATENTS Horton et al 220-26 Diekmann 220--26 Cibulka 220--26 Horner 220-26 Wiggins 220-26 Fino 220-26 De Bock 22026 THERON E. CONDON, Primary Examiner.

JAMES R. GARRETT, Assistant Examiner. 

